yii2.0使用Plupload实现带缩放功能的多图上传

<?= \common\widgets\plupload::widget([
 'model'=>$model,
 'attribute'=>'cover_img',
 'url'=>'/file/upload',//处理文件上传控制器
])?>

<?php
namespace common\widgets;

use backend\assets\uploadasset;
use yii;
use yii\helpers\html;
use yii\base\exception;

class plupload extends yii\bootstrap\widget{
 public $model;
 public $attribute;
 public $name;
 public $url;

 private $_html;


 public function init(){
  parent::init();
 if(!$this->url){
 throw new exception('url参数不能为空');
 }
  if(!$this->model){
   throw new exception('model属性不能为空');
  }
  if(!$this->attribute){
   throw new exception('attribute属性不能为空');
  }
 }
 public function run(){
  $model = $this->model;
  $attribute = $this->attribute;
  $path = $model->$attribute?$model->$attribute:"/images/noimage.gif";//显示文章图片或者默认图片
  $this->_html.='<div class="form-group field-article-author" id="container">';
  $this->_html.=html::activelabel($model,$attribute);
  $this->_html.=html::activehiddeninput($model,$attribute,['id'=>'hidden_input','value'=>$path]);
  $this->_html .= '<div id="pickfiles" style="height:50px;min-width:50px;max-width: 300px;overflow: hidden;"><img height="50" src="'.$path.'" /></div>';
  $this->_html.='</div> ';
  uploadasset::register($this->view);
 $this->view->registerjs(
 '$(function(){
    initcoverimageuploader("pickfiles","container","2mb","'.$this->url.'","'.yii::$app->request->getcsrftoken().'");
   });'
 );

  return $this->_html;
 }

}

<?php
namespace backend\assets;

use yii\web\assetbundle;

class uploadasset extends assetbundle
{
 public $basepath = '@webroot';
 public $baseurl = '@web';
 public $css = [
 ];
 public $js = [
  'js/upload.js'
 ];
 public $depends = [
  'backend\assets\pluploadasset',
 ];
}

function initcoverimageuploader(buttonid,contatinerid,maxfilesize,url,csrftoken){
 var uploader = new plupload.uploader({
  runtimes : 'html5,flash,silverlight,html4',
  browse_button :buttonid, // you can pass an id...
  container: contatinerid, // ... or dom element itself
  url : url,
  flash_swf_url : '@vendor/moxiecode/plupload/js/moxie.swf',
  silverlight_xap_url : '@vendor/moxiecode/plupload//js/moxie.xap',

  filters : {
   max_file_size : maxfilesize,
   mime_types: [
    {title : "image files", extensions : "jpg,gif,png"},
    {title : "zip files", extensions : "zip"}
   ]
  },
  multipart_params:{
   '_csrf':csrftoken
  },
  init: {
   filesadded: function(up, files) {
    uploader.start();
   },
   uploadprogress: function(up, file) {
    $('#'+contatinerid+' p').text('已上传:'+file.percent+'%');
   },
   fileuploaded:function (up, file, result) {
    result = $.parsejson(result.response);
    if(result.code == 0){
     $('#'+buttonid).html('<img src="'+result.path+'" height="50" />');
     $('#hidden_input').val(result.path);
     //console.log(result.message);
    }
   },
   error: function(up, err) {
    document.getelementbyid('console').appendchild(document.createtextnode("\nerror #" + err.code + ": " + err.message));
   }
  }
 });

 uploader.init();
}

<?php

namespace backend\assets;

use yii\web\assetbundle;


class pluploadasset extends assetbundle
{
 public $sourcepath = '@vendor/moxiecode/plupload';

 public $css = [
 ];
 public $js = [
  'js/plupload.full.min.js',
 ];
 public $depends = [
  'yii\web\jqueryasset',
 ];
}

class filecontroller extends basecontroller
{
 public function actionupload(){
  yii::$app->response->format=response::format_json;
  $model = new imageupload();
  $model->fileinputname = 'file';
  if($model->save()){
   return ['code'=>0,'message'=>$model->getmessage(),'path'=>$model->geturlpath()];
  }else{
   return ['code'=>1,'message'=>$model->getmessage()];
  }
 }

}

<?php

namespace common\models;

use yii\base\exception;
use yii\helpers\filehelper;
use yii\web\uploadedfile;

class imageupload extends \yii\base\object
{
 public $fileinputname = 'file';//上传表单 file name
 public $savepath ;//图像保存根位置
 public $allowext = ['jpg','png','jpeg','gif','bmp'];//允许上传后缀
 public $maxfilesize=1024100000;//最大大小
 public $allowtype = ['image/jpeg','image/bmp','image/gif','image/png','image/pjpeg','image/bmp','image/gif','image/x-png','image/pjpeg','image/bmp', 'image/gif' ,'image/x-png','image/pjpeg','image/bmp','image/gif','image/x-png'];

 private $_uploadfile;//上传文件
 private $filepath;//文件路径
 private $urlpath;//访问路径
 private $res=false;//返回状态
 private $message;//返回信息

 public function getmessage(){
  return $this->message;
 }
 public function geturlpath(){
  return $this->urlpath;
 }

 public function init(){
  if(!$this->fileinputname) throw new exception('fileinputname属性不能为空');

  if(!$this->savepath) $this->savepath = \yii::$app->basepath.'/web/uploads/images';
  $this->savepath = rtrim($this->savepath,'/');
  if(!file_exists($this->savepath)){
   if(! filehelper::createdirectory($this->savepath)){
    $this->message = '没有权限创建'.$this->savepath;
    return false;
   }
  }

  $this->_uploadfile = uploadedfile::getinstancebyname($this->fileinputname);
  if(!$this->_uploadfile){
   $this->message = '没有找到上传文件';
   return false;
  }
  if($this->_uploadfile->error){
   $this->message = '上传失败';
   return false;
  }

  if(!in_array($this->extension,$this->allowext) || !in_array($this->type,$this->allowtype)){
   $this->message = '该文件类型不允许上传';
   return false;
  }

  if($this->_uploadfile->size> $this->maxfilesize){
   $this->message = '文件过大';
   return false;
  }

  $path = date('y-m',time());
  if(!file_exists($this->savepath.'/'.$path)){
   filehelper::createdirectory($this->savepath.'/'.$path);
  }
  $name = substr(\yii::$app->security->generaterandomstring(),-4,4);
  $this->filepath = $this->savepath.'/'.$path.'/'.$this->basename.'--'.$name.'.'.$this->extension;
  $this->urlpath = '/uploads/images/'.$path.'/'.$this->basename.'--'.$name.'.'.$this->extension;
 }

 public function save(){
  if($this->_uploadfile->saveas($this->filepath)){
   $this->createthumbnail($this->filepath);//缩放图片
   $this->res = true;
  }else{
   $this->res = false;
  }
  if($this->res){
   $this->message = $this->_uploadfile->basename.'.'.$this->_uploadfile->extension.'上传成功';
  }else{
   $this->message = $this->_uploadfile->basename.'.'.$this->_uploadfile->extension.'上传失败';
  }
  return $this->res;
 }

 /**
  * 获取文件名字
  * @return null
  */
 public function getbasename(){
  if($this->_uploadfile){
   return $this->_uploadfile->basename;
  }else{
   return null;
  }
 }
 /**
  * 返回文件后缀
  * @return null
  */
 public function getextension(){
  if($this->_uploadfile){
   return $this->_uploadfile->extension;
  }else{
   return null;
  }
 }
 /**
  * 返回文件类型
  * @return mixed
  */
 public function gettype(){
  if($this->_uploadfile){
   return $this->_uploadfile->type;
  }
  return null;
 }

 /**
  * 生成保持原图纵横比的缩略图，支持.png .jpg .gif
  * 缩略图类型统一为.png格式
  * $srcfile  原图像文件名称
  * $tofile  缩略图文件名称，为空覆盖原图像文件
  * $tow   缩略图宽
  * $toh   缩略图高
  * @return bool
  */
 public static function createthumbnail($srcfile, $tofile="", $tow=100, $toh=100)
 {
  if ($tofile == "") $tofile = $srcfile;

  $data = getimagesize($srcfile);//返回含有4个单元的数组，0-宽，1-高，2-图像类型，3-宽高的文本描述。
  if (!$data) return false;
  //将文件载入到资源变量im中
  switch ($data[2]) //1-gif，2-jpg，3-png
  {
   case 1:
    if(!function_exists("imagecreatefromgif")) return false;
    $im = imagecreatefromgif($srcfile);
    break;
   case 2:
    if(!function_exists("imagecreatefromjpeg")) return false;
    $im = imagecreatefromjpeg($srcfile);
    break;
   case 3:
    if(!function_exists("imagecreatefrompng")) return false;
    $im = imagecreatefrompng($srcfile);
    break;
  }
  //计算缩略图的宽高
  $srcw = imagesx($im);
  $srch = imagesy($im);
  $towh = $tow / $toh;
  $srcwh = $srcw / $srch;
  if ($towh <= $srcwh) {
   $ftow = $tow;
   $ftoh = (int)($ftow * ($srch / $srcw));
  } else {
   $ftoh = $toh;
   $ftow = (int)($ftoh * ($srcw / $srch));
  }

  if (function_exists("imagecreatetruecolor")) {
   $ni = imagecreatetruecolor($ftow, $ftoh); //新建一个真彩色图像
   if ($ni) {
    //重采样拷贝部分图像并调整大小 可保持较好的清晰度
    imagecopyresampled($ni, $im, 0, 0, 0, 0, $ftow, $ftoh, $srcw, $srch);
   } else {
    //拷贝部分图像并调整大小
    $ni = imagecreate($ftow, $ftoh);
    imagecopyresized($ni, $im, 0, 0, 0, 0, $ftow, $ftoh, $srcw, $srch);
   }
  } else {
   $ni = imagecreate($ftow, $ftoh);
   imagecopyresized($ni, $im, 0, 0, 0, 0, $ftow, $ftoh, $srcw, $srch);
  }

  switch ($data[2]) //1-gif，2-jpg，3-png
  {
   case 1:
    imagegif($ni, $tofile);
    break;
   case 2:
    imagejpeg($ni, $tofile);
    break;
   case 3:
    imagepng($ni, $tofile);
    break;
  }
  imagedestroy($ni);
  imagedestroy($im);
  return $tofile;
 }
}